@node gnutls-serv Invocation
@section Invoking gnutls-serv
@pindex gnutls-serv
@ignore
# -*- buffer-read-only: t -*- vi: set ro:
#
# DO NOT EDIT THIS FILE (invoke-gnutls-serv.texi)
#
# It has been AutoGen-ed
# From the definitions ../src/serv-args.def
# and the template file agtexi-cmd.tpl
@end ignore
Server program that listens to incoming TLS connections.
This section was generated by @strong{AutoGen},
using the @code{agtexi-cmd} template and the option descriptions for the @code{gnutls-serv} program.
This software is released under the GNU General Public License, version 3 or later.
@anchor{gnutls-serv usage}
@subheading gnutls-serv help/usage (@option{--help})
@cindex gnutls-serv help
This is the automatically generated usage text for gnutls-serv.
The text printed is the same whether selected with the @code{help} option
(@option{--help}) or the @code{more-help} option (@option{--more-help}). @code{more-help} will print
the usage text by passing it through a pager program.
@code{more-help} is disabled on platforms without a working
@code{fork(2)} function. The @code{PAGER} environment variable is
used to select the program, defaulting to @file{more}. Both will exit
with a status code of 0.
@exampleindent 0
@example
gnutls-serv - GnuTLS server
Usage: gnutls-serv [ -<flag> [<val>] | --<name>[@{=| @}<val>] ]...
-d, --debug=num Enable debugging
- it must be in the range:
0 to 9999
--sni-hostname=str Server's hostname for server name extension
--sni-hostname-fatal Send fatal alert on sni-hostname mismatch
--alpn=str Specify ALPN protocol to be enabled by the server
- may appear multiple times
--alpn-fatal Send fatal alert on non-matching ALPN name
--noticket Don't accept session tickets
--earlydata Accept early data
--maxearlydata=num The maximum early data size to accept
- it must be in the range:
1 to 4294967295
--nocookie Don't require cookie on DTLS sessions
-g, --generate Generate Diffie-Hellman parameters
-q, --quiet Suppress some messages
--nodb Do not use a resumption database
--http Act as an HTTP server
--echo Act as an Echo server
-u, --udp Use DTLS (datagram TLS) over UDP
--mtu=num Set MTU for datagram TLS
- it must be in the range:
0 to 17000
--srtp-profiles=str Offer SRTP profiles
-a, --disable-client-cert Do not request a client certificate
- prohibits the option 'require-client-cert'
-r, --require-client-cert Require a client certificate
--verify-client-cert If a client certificate is sent then verify it.
-b, --heartbeat Activate heartbeat support
--x509fmtder Use DER format for certificates to read from
--priority=str Priorities string
--dhparams=file DH params file to use
- file must pre-exist
--x509cafile=str Certificate file or PKCS #11 URL to use
--x509crlfile=file CRL file to use
- file must pre-exist
--x509keyfile=str X.509 key file or PKCS #11 URL to use
- may appear multiple times
--x509certfile=str X.509 Certificate file or PKCS #11 URL to use
- may appear multiple times
--rawpkkeyfile=str Private key file (PKCS #8 or PKCS #12) or PKCS #11 URL to use
- may appear multiple times
--rawpkfile=str Raw public-key file to use
- requires the option 'rawpkkeyfile'
- may appear multiple times
--srppasswd=file SRP password file to use
- file must pre-exist
--srppasswdconf=file SRP password configuration file to use
- file must pre-exist
--pskpasswd=file PSK password file to use
- file must pre-exist
--pskhint=str PSK identity hint to use
--ocsp-response=str The OCSP response to send to client
- may appear multiple times
--ignore-ocsp-response-errors Ignore any errors when setting the OCSP response
-p, --port=num The port to connect to
-l, --list Print a list of the supported algorithms and modes
--provider=file Specify the PKCS #11 provider library
- file must pre-exist
--keymatexport=str Label used for exporting keying material
--keymatexportsize=num Size of the exported keying material
--recordsize=num The maximum record size to advertise
- it must be in the range:
0 to 16384
--httpdata=file The data used as HTTP response
- file must pre-exist
-v, --version[=arg] output version information and exit
-h, --help display extended usage information and exit
-!, --more-help extended usage information passed thru pager
Options are specified by doubled hyphens and their name or by a single
hyphen and the flag character.
Server program that listens to incoming TLS connections.
@end example
@exampleindent 4
@anchor{gnutls-serv debug}
@subheading debug option (-d)
This is the ``enable debugging'' option.
This option takes a number argument.
Specifies the debug level.
@anchor{gnutls-serv sni-hostname}
@subheading sni-hostname option
This is the ``server's hostname for server name extension'' option.
This option takes a string argument.
Server name of type host_name that the server will recognise as its own. If the server receives client hello with different name, it will send a warning-level unrecognized_name alert.
@anchor{gnutls-serv alpn}
@subheading alpn option
This is the ``specify alpn protocol to be enabled by the server'' option.
This option takes a string argument.
@noindent
This option has some usage constraints. It:
@itemize @bullet
@item
may appear an unlimited number of times.
@end itemize
Specify the (textual) ALPN protocol for the server to use.
@anchor{gnutls-serv require-client-cert}
@subheading require-client-cert option (-r)
This is the ``require a client certificate'' option.
This option before 3.6.0 used to imply --verify-client-cert.
Since 3.6.0 it will no longer verify the certificate by default.
@anchor{gnutls-serv verify-client-cert}
@subheading verify-client-cert option
This is the ``if a client certificate is sent then verify it.'' option.
Do not require, but if a client certificate is sent then verify it and close the connection if invalid.
@anchor{gnutls-serv heartbeat}
@subheading heartbeat option (-b)
This is the ``activate heartbeat support'' option.
Regularly ping client via heartbeat extension messages
@anchor{gnutls-serv priority}
@subheading priority option
This is the ``priorities string'' option.
This option takes a string argument.
TLS algorithms and protocols to enable. You can
use predefined sets of ciphersuites such as PERFORMANCE,
NORMAL, SECURE128, SECURE256. The default is NORMAL.
Check the GnuTLS manual on section ``Priority strings'' for more
information on allowed keywords
@anchor{gnutls-serv x509keyfile}
@subheading x509keyfile option
This is the ``x.509 key file or pkcs #11 url to use'' option.
This option takes a string argument.
@noindent
This option has some usage constraints. It:
@itemize @bullet
@item
may appear an unlimited number of times.
@end itemize
Specify the private key file or URI to use; it must correspond to
the certificate specified in --x509certfile. Multiple keys and certificates
can be specified with this option and in that case each occurrence of keyfile
must be followed by the corresponding x509certfile or vice-versa.
@anchor{gnutls-serv x509certfile}
@subheading x509certfile option
This is the ``x.509 certificate file or pkcs #11 url to use'' option.
This option takes a string argument.
@noindent
This option has some usage constraints. It:
@itemize @bullet
@item
may appear an unlimited number of times.
@end itemize
Specify the certificate file or URI to use; it must correspond to
the key specified in --x509keyfile. Multiple keys and certificates
can be specified with this option and in that case each occurrence of keyfile
must be followed by the corresponding x509certfile or vice-versa.
@anchor{gnutls-serv x509dsakeyfile}
@subheading x509dsakeyfile option
This is an alias for the @code{x509keyfile} option,
@pxref{gnutls-serv x509keyfile, the x509keyfile option documentation}.
@anchor{gnutls-serv x509dsacertfile}
@subheading x509dsacertfile option
This is an alias for the @code{x509certfile} option,
@pxref{gnutls-serv x509certfile, the x509certfile option documentation}.
@anchor{gnutls-serv x509ecckeyfile}
@subheading x509ecckeyfile option
This is an alias for the @code{x509keyfile} option,
@pxref{gnutls-serv x509keyfile, the x509keyfile option documentation}.
@anchor{gnutls-serv x509ecccertfile}
@subheading x509ecccertfile option
This is an alias for the @code{x509certfile} option,
@pxref{gnutls-serv x509certfile, the x509certfile option documentation}.
@anchor{gnutls-serv rawpkkeyfile}
@subheading rawpkkeyfile option
This is the ``private key file (pkcs #8 or pkcs #12) or pkcs #11 url to use'' option.
This option takes a string argument.
@noindent
This option has some usage constraints. It:
@itemize @bullet
@item
may appear an unlimited number of times.
@end itemize
Specify the private key file or URI to use; it must correspond to
the raw public-key specified in --rawpkfile. Multiple key pairs
can be specified with this option and in that case each occurrence of keyfile
must be followed by the corresponding rawpkfile or vice-versa.
In order to instruct the application to negotiate raw public keys one
must enable the respective certificate types via the priority strings (i.e. CTYPE-CLI-*
and CTYPE-SRV-* flags).
Check the GnuTLS manual on section ``Priority strings'' for more
information on how to set certificate types.
@anchor{gnutls-serv rawpkfile}
@subheading rawpkfile option
This is the ``raw public-key file to use'' option.
This option takes a string argument.
@noindent
This option has some usage constraints. It:
@itemize @bullet
@item
may appear an unlimited number of times.
@item
must appear in combination with the following options:
rawpkkeyfile.
@end itemize
Specify the raw public-key file to use; it must correspond to
the private key specified in --rawpkkeyfile. Multiple key pairs
can be specified with this option and in that case each occurrence of keyfile
must be followed by the corresponding rawpkfile or vice-versa.
In order to instruct the application to negotiate raw public keys one
must enable the respective certificate types via the priority strings (i.e. CTYPE-CLI-*
and CTYPE-SRV-* flags).
Check the GnuTLS manual on section ``Priority strings'' for more
information on how to set certificate types.
@anchor{gnutls-serv ocsp-response}
@subheading ocsp-response option
This is the ``the ocsp response to send to client'' option.
This option takes a string argument.
@noindent
This option has some usage constraints. It:
@itemize @bullet
@item
may appear an unlimited number of times.
@end itemize
If the client requested an OCSP response, return data from this file to the client.
@anchor{gnutls-serv ignore-ocsp-response-errors}
@subheading ignore-ocsp-response-errors option
This is the ``ignore any errors when setting the ocsp response'' option.
That option instructs gnutls to not attempt to match the provided OCSP responses with the certificates.
@anchor{gnutls-serv list}
@subheading list option (-l)
This is the ``print a list of the supported algorithms and modes'' option.
Print a list of the supported algorithms and modes. If a priority string is given then only the enabled ciphersuites are shown.
@anchor{gnutls-serv provider}
@subheading provider option
This is the ``specify the pkcs #11 provider library'' option.
This option takes a file argument.
This will override the default options in /etc/gnutls/pkcs11.conf
@anchor{gnutls-serv exit status}
@subheading gnutls-serv exit status
One of the following exit values will be returned:
@table @samp
@item 0 (EXIT_SUCCESS)
Successful program execution.
@item 1 (EXIT_FAILURE)
The operation failed or the command syntax was not valid.
@end table
@anchor{gnutls-serv See Also}
@subheading gnutls-serv See Also
gnutls-cli-debug(1), gnutls-cli(1)
@anchor{gnutls-serv Examples}
@subheading gnutls-serv Examples
Running your own TLS server based on GnuTLS can be useful when
debugging clients and/or GnuTLS itself. This section describes how to
use @code{gnutls-serv} as a simple HTTPS server.
The most basic server can be started as:
@example
gnutls-serv --http --priority "NORMAL:+ANON-ECDH:+ANON-DH"
@end example
It will only support anonymous ciphersuites, which many TLS clients
refuse to use.
The next step is to add support for X.509. First we generate a CA:
@example
$ certtool --generate-privkey > x509-ca-key.pem
$ echo 'cn = GnuTLS test CA' > ca.tmpl
$ echo 'ca' >> ca.tmpl
$ echo 'cert_signing_key' >> ca.tmpl
$ certtool --generate-self-signed --load-privkey x509-ca-key.pem \
--template ca.tmpl --outfile x509-ca.pem
@end example
Then generate a server certificate. Remember to change the dns_name
value to the name of your server host, or skip that command to avoid
the field.
@example
$ certtool --generate-privkey > x509-server-key.pem
$ echo 'organization = GnuTLS test server' > server.tmpl
$ echo 'cn = test.gnutls.org' >> server.tmpl
$ echo 'tls_www_server' >> server.tmpl
$ echo 'encryption_key' >> server.tmpl
$ echo 'signing_key' >> server.tmpl
$ echo 'dns_name = test.gnutls.org' >> server.tmpl
$ certtool --generate-certificate --load-privkey x509-server-key.pem \
--load-ca-certificate x509-ca.pem --load-ca-privkey x509-ca-key.pem \
--template server.tmpl --outfile x509-server.pem
@end example
For use in the client, you may want to generate a client certificate
as well.
@example
$ certtool --generate-privkey > x509-client-key.pem
$ echo 'cn = GnuTLS test client' > client.tmpl
$ echo 'tls_www_client' >> client.tmpl
$ echo 'encryption_key' >> client.tmpl
$ echo 'signing_key' >> client.tmpl
$ certtool --generate-certificate --load-privkey x509-client-key.pem \
--load-ca-certificate x509-ca.pem --load-ca-privkey x509-ca-key.pem \
--template client.tmpl --outfile x509-client.pem
@end example
To be able to import the client key/certificate into some
applications, you will need to convert them into a PKCS#12 structure.
This also encrypts the security sensitive key with a password.
@example
$ certtool --to-p12 --load-ca-certificate x509-ca.pem \
--load-privkey x509-client-key.pem --load-certificate x509-client.pem \
--outder --outfile x509-client.p12
@end example
For icing, we'll create a proxy certificate for the client too.
@example
$ certtool --generate-privkey > x509-proxy-key.pem
$ echo 'cn = GnuTLS test client proxy' > proxy.tmpl
$ certtool --generate-proxy --load-privkey x509-proxy-key.pem \
--load-ca-certificate x509-client.pem --load-ca-privkey x509-client-key.pem \
--load-certificate x509-client.pem --template proxy.tmpl \
--outfile x509-proxy.pem
@end example
Then start the server again:
@example
$ gnutls-serv --http \
--x509cafile x509-ca.pem \
--x509keyfile x509-server-key.pem \
--x509certfile x509-server.pem
@end example
Try connecting to the server using your web browser. Note that the
server listens to port 5556 by default.
While you are at it, to allow connections using ECDSA, you can also
create a ECDSA key and certificate for the server. These credentials
will be used in the final example below.
@example
$ certtool --generate-privkey --ecdsa > x509-server-key-ecc.pem
$ certtool --generate-certificate --load-privkey x509-server-key-ecc.pem \
--load-ca-certificate x509-ca.pem --load-ca-privkey x509-ca-key.pem \
--template server.tmpl --outfile x509-server-ecc.pem
@end example
The next step is to add support for SRP authentication. This requires
an SRP password file created with @code{srptool}.
To start the server with SRP support:
@example
gnutls-serv --http --priority NORMAL:+SRP-RSA:+SRP \
--srppasswdconf srp-tpasswd.conf \
--srppasswd srp-passwd.txt
@end example
Let's also start a server with support for PSK. This would require
a password file created with @code{psktool}.
@example
gnutls-serv --http --priority NORMAL:+ECDHE-PSK:+PSK \
--pskpasswd psk-passwd.txt
@end example
If you want a server with support for raw public-keys we can also add these
credentials. Note however that there is no identity information linked to these
keys as is the case with regular x509 certificates. Authentication must be done
via different means. Also we need to explicitly enable raw public-key certificates
via the priority strings.
@example
gnutls-serv --http --priority NORMAL:+CTYPE-CLI-RAWPK:+CTYPE-SRV-RAWPK \
--rawpkfile srv.rawpk.pem \
--rawpkkeyfile srv.key.pem
@end example
Finally, we start the server with all the earlier parameters and you
get this command:
@example
gnutls-serv --http --priority NORMAL:+PSK:+SRP:+CTYPE-CLI-RAWPK:+CTYPE-SRV-RAWPK \
--x509cafile x509-ca.pem \
--x509keyfile x509-server-key.pem \
--x509certfile x509-server.pem \
--x509keyfile x509-server-key-ecc.pem \
--x509certfile x509-server-ecc.pem \
--srppasswdconf srp-tpasswd.conf \
--srppasswd srp-passwd.txt \
--pskpasswd psk-passwd.txt \
--rawpkfile srv.rawpk.pem \
--rawpkkeyfile srv.key.pem
@end example